Xamarin Public Jenkins (auto-signing) ef583813eb Imported Upstream version 6.4.0.137
Former-commit-id: 943baa9f16a098c33e129777827f3a9d20da00d6
2019-07-26 19:53:28 +00:00

484 lines
14 KiB
C#

using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Runtime.Serialization;
namespace System
{
/* Contains the rarely used fields of Delegate */
sealed class DelegateData
{
public Type? target_type;
public string? method_name;
public bool curried_first_arg;
}
[StructLayout (LayoutKind.Sequential)]
partial class Delegate
{
#region Sync with object-internals.h
IntPtr method_ptr;
IntPtr invoke_impl;
object? _target;
IntPtr method;
IntPtr delegate_trampoline;
IntPtr extra_arg;
IntPtr method_code;
IntPtr interp_method;
IntPtr interp_invoke_impl;
MethodInfo? method_info;
// Keep a ref of the MethodInfo passed to CreateDelegate.
// Used to keep DynamicMethods alive.
MethodInfo? original_method_info;
DelegateData data;
bool method_is_virtual;
#endregion
protected Delegate (object target, string method)
{
if (target is null)
throw new ArgumentNullException (nameof (target));
if (method is null)
throw new ArgumentNullException (nameof (method));
this._target = target;
this.data = new DelegateData () {
method_name = method
};
}
protected Delegate (Type target, string method)
{
if (target is null)
throw new ArgumentNullException (nameof (target));
if (target.ContainsGenericParameters)
throw new ArgumentException (SR.Arg_UnboundGenParam, nameof (target));
if (method is null)
throw new ArgumentNullException (nameof (method));
if (!target.IsRuntimeImplemented ())
throw new ArgumentException (SR.Argument_MustBeRuntimeType, nameof (target));
this.data = new DelegateData () {
method_name = method,
target_type = target
};
}
public object? Target => GetTarget ();
internal virtual object? GetTarget () => _target;
public static Delegate CreateDelegate (Type type, object? firstArgument, MethodInfo method, bool throwOnBindFailure)
{
return CreateDelegate (type, firstArgument, method, throwOnBindFailure, true)!;
}
public static Delegate? CreateDelegate (Type type, MethodInfo method, bool throwOnBindFailure)
{
return CreateDelegate (type, null, method, throwOnBindFailure, false);
}
static Delegate? CreateDelegate (Type type, object? firstArgument, MethodInfo method, bool throwOnBindFailure, bool allowClosed)
{
if (type is null)
throw new ArgumentNullException (nameof (type));
if (method is null)
throw new ArgumentNullException (nameof (method));
if (!(type is RuntimeType rtType))
throw new ArgumentException (SR.Argument_MustBeRuntimeType, nameof (type));
if (!(method is RuntimeMethodInfo || method is System.Reflection.Emit.DynamicMethod))
throw new ArgumentException (SR.Argument_MustBeRuntimeMethodInfo, nameof (method));
if (!rtType.IsDelegate ())
throw new ArgumentException (SR.Arg_MustBeDelegate, nameof (type));
if (!IsMatchingCandidate (type, firstArgument, method, allowClosed, out DelegateData? delegate_data)) {
if (throwOnBindFailure)
throw new ArgumentException (SR.Arg_DlgtTargMeth);
return null;
}
Delegate? d = CreateDelegate_internal (type, firstArgument, method, throwOnBindFailure);
if (d != null) {
d.original_method_info = method;
d.data = delegate_data!;
}
return d;
}
public static Delegate? CreateDelegate (Type type, object target, string method, bool ignoreCase, bool throwOnBindFailure)
{
if (type is null)
throw new ArgumentNullException (nameof (type));
if (target is null)
throw new ArgumentNullException (nameof (target));
if (method is null)
throw new ArgumentNullException (nameof (method));
if (!(type is RuntimeType rtType))
throw new ArgumentException (SR.Argument_MustBeRuntimeType, nameof (type));
if (!rtType.IsDelegate ())
throw new ArgumentException (SR.Arg_MustBeDelegate, nameof (type));
MethodInfo? info = GetCandidateMethod (type, target.GetType (), method, BindingFlags.Instance, ignoreCase);
if (info is null) {
if (throwOnBindFailure)
throw new ArgumentException (SR.Arg_DlgtTargMeth);
return null;
}
return CreateDelegate_internal (type, null, info, throwOnBindFailure);
}
public static Delegate? CreateDelegate (Type type, Type target, string method, bool ignoreCase, bool throwOnBindFailure)
{
if (type is null)
throw new ArgumentNullException (nameof (type));
if (target is null)
throw new ArgumentNullException (nameof (target));
if (target.ContainsGenericParameters)
throw new ArgumentException (SR.Arg_UnboundGenParam, nameof (target));
if (method is null)
throw new ArgumentNullException (nameof (method));
if (!(type is RuntimeType rtType))
throw new ArgumentException (SR.Argument_MustBeRuntimeType, nameof (type));
if (!target.IsRuntimeImplemented ())
throw new ArgumentException (SR.Argument_MustBeRuntimeType, nameof (target));
if (!rtType.IsDelegate ())
throw new ArgumentException (SR.Arg_MustBeDelegate, nameof (type));
MethodInfo? info = GetCandidateMethod (type, target, method, BindingFlags.Static, ignoreCase);
if (info is null) {
if (throwOnBindFailure)
throw new ArgumentException (SR.Arg_DlgtTargMeth);
return null;
}
return CreateDelegate_internal (type, null, info, throwOnBindFailure);
}
static MethodInfo? GetCandidateMethod (Type type, Type target, string method, BindingFlags bflags, bool ignoreCase)
{
MethodInfo? invoke = type.GetMethod ("Invoke");
if (invoke is null)
return null;
ParameterInfo [] delargs = invoke.GetParametersInternal ();
Type[] delargtypes = new Type [delargs.Length];
for (int i = 0; i < delargs.Length; i++)
delargtypes [i] = delargs [i].ParameterType;
/*
* since we need to walk the inheritance chain anyway to
* find private methods, adjust the bindingflags to ignore
* inherited methods
*/
BindingFlags flags = BindingFlags.ExactBinding |
BindingFlags.Public | BindingFlags.NonPublic |
BindingFlags.DeclaredOnly | bflags;
if (ignoreCase)
flags |= BindingFlags.IgnoreCase;
for (Type? targetType = target; targetType != null; targetType = targetType.BaseType) {
MethodInfo? mi = targetType.GetMethod (method, flags, null, delargtypes, Array.Empty<ParameterModifier>());
if (mi != null && IsReturnTypeMatch (invoke.ReturnType!, mi.ReturnType!)) {
return mi;
}
}
return null;
}
static bool IsMatchingCandidate (Type type, object? target, MethodInfo method, bool allowClosed, out DelegateData? delegateData)
{
MethodInfo? invoke = type.GetMethod ("Invoke");
if (invoke == null || !IsReturnTypeMatch (invoke.ReturnType!, method.ReturnType!)) {
delegateData = null;
return false;
}
ParameterInfo[] delargs = invoke.GetParametersInternal ();
ParameterInfo[] args = method.GetParametersInternal ();
bool argLengthMatch;
if (target != null) {
// delegate closed over target
if (!method.IsStatic)
// target is passed as this
argLengthMatch = (args.Length == delargs.Length);
else
// target is passed as the first argument to the static method
argLengthMatch = (args.Length == delargs.Length + 1);
} else {
if (!method.IsStatic) {
//
// Net 2.0 feature. The first argument of the delegate is passed
// as the 'this' argument to the method.
//
argLengthMatch = (args.Length + 1 == delargs.Length);
if (!argLengthMatch)
// closed over a null reference
argLengthMatch = (args.Length == delargs.Length);
} else {
argLengthMatch = (args.Length == delargs.Length);
if (!argLengthMatch)
// closed over a null reference
argLengthMatch = args.Length == delargs.Length + 1;
}
}
if (!argLengthMatch) {
delegateData = null;
return false;
}
bool argsMatch;
delegateData = new DelegateData ();
if (target != null) {
if (!method.IsStatic) {
argsMatch = IsArgumentTypeMatchWithThis (target.GetType (), method.DeclaringType!, true);
for (int i = 0; i < args.Length; i++)
argsMatch &= IsArgumentTypeMatch (delargs [i].ParameterType, args [i].ParameterType);
} else {
argsMatch = IsArgumentTypeMatch (target.GetType (), args [0].ParameterType);
for (int i = 1; i < args.Length; i++)
argsMatch &= IsArgumentTypeMatch (delargs [i - 1].ParameterType, args [i].ParameterType);
delegateData.curried_first_arg = true;
}
} else {
if (!method.IsStatic) {
if (args.Length + 1 == delargs.Length) {
// The first argument should match this
argsMatch = IsArgumentTypeMatchWithThis (delargs [0].ParameterType, method.DeclaringType!, false);
for (int i = 0; i < args.Length; i++)
argsMatch &= IsArgumentTypeMatch (delargs [i + 1].ParameterType, args [i].ParameterType);
} else {
// closed over a null reference
argsMatch = allowClosed;
for (int i = 0; i < args.Length; i++)
argsMatch &= IsArgumentTypeMatch (delargs [i].ParameterType, args [i].ParameterType);
}
} else {
if (delargs.Length + 1 == args.Length) {
// closed over a null reference
argsMatch = !(args [0].ParameterType.IsValueType || args [0].ParameterType.IsByRef) && allowClosed;
for (int i = 0; i < delargs.Length; i++)
argsMatch &= IsArgumentTypeMatch (delargs [i].ParameterType, args [i + 1].ParameterType);
delegateData.curried_first_arg = true;
} else {
argsMatch = true;
for (int i = 0; i < args.Length; i++)
argsMatch &= IsArgumentTypeMatch (delargs [i].ParameterType, args [i].ParameterType);
}
}
}
return argsMatch;
}
static bool IsReturnTypeMatch (Type delReturnType, Type returnType)
{
bool returnMatch = returnType == delReturnType;
if (!returnMatch) {
// Delegate covariance
if (!returnType.IsValueType && delReturnType.IsAssignableFrom (returnType))
returnMatch = true;
}
return returnMatch;
}
static bool IsArgumentTypeMatch (Type delArgType, Type argType)
{
bool match = delArgType == argType;
// Delegate contravariance
if (!match) {
if (!argType.IsValueType && argType.IsAssignableFrom (delArgType))
match = true;
}
// enum basetypes
if (!match) {
if (delArgType.IsEnum && Enum.GetUnderlyingType (delArgType) == argType)
match = true;
else if (argType.IsEnum && Enum.GetUnderlyingType (argType) == delArgType)
match = true;
}
return match;
}
static bool IsArgumentTypeMatchWithThis (Type delArgType, Type argType, bool boxedThis)
{
bool match;
if (argType.IsValueType)
match = delArgType.IsByRef && delArgType.GetElementType () == argType ||
(boxedThis && delArgType == argType);
else
match = delArgType == argType || argType.IsAssignableFrom (delArgType);
return match;
}
protected virtual object? DynamicInvokeImpl (object?[]? args)
{
if (Method is null) {
#nullable disable
// FIXME: This code cannot handle null argument values
Type[] mtypes = new Type [args.Length];
for (int i = 0; i < args.Length; ++i) {
mtypes [i] = args [i].GetType ();
}
method_info = _target.GetType ().GetMethod (data.method_name, mtypes);
#nullable restore
}
var target = _target;
if (data is null)
data = CreateDelegateData ();
// replace all Type.Missing with default values defined on parameters of the delegate if any
MethodInfo? invoke = GetType ().GetMethod ("Invoke");
if (invoke != null && args != null) {
ParameterInfo[] delegateParameters = invoke.GetParameters ();
for (int i = 0; i < args.Length; i++) {
if (args [i] == Type.Missing) {
ParameterInfo dlgParam = delegateParameters [i];
if (dlgParam.HasDefaultValue) {
args [i] = dlgParam.DefaultValue;
}
}
}
}
if (Method.IsStatic) {
//
// The delegate is bound to _target
//
if (data.curried_first_arg) {
if (args is null) {
args = new object?[] { target };
} else {
Array.Resize (ref args, args.Length + 1);
Array.Copy (args, 0, args, 1, args.Length - 1);
args [0] = target;
}
target = null;
}
} else {
if (_target is null && args?.Length > 0) {
target = args [0];
Array.Copy (args, 1, args, 0, args.Length - 1);
Array.Resize (ref args, args.Length - 1);
}
}
return Method.Invoke (target, args);
}
public override bool Equals (object? obj)
{
if (!(obj is Delegate d) || !InternalEqualTypes (this, obj))
return false;
// Do not compare method_ptr, since it can point to a trampoline
if (d._target == _target && d.Method == Method) {
if (d.data != null || data != null) {
/* Uncommon case */
if (d.data != null && data != null)
return (d.data.target_type == data.target_type && d.data.method_name == data.method_name);
else {
if (d.data != null)
return d.data.target_type is null;
if (data != null)
return data.target_type is null;
return false;
}
}
return true;
}
return false;
}
public override int GetHashCode ()
{
MethodInfo? m = Method;
return (m != null ? m.GetHashCode () : GetType ().GetHashCode ()) ^ RuntimeHelpers.GetHashCode (_target);
}
protected virtual MethodInfo GetMethodImpl ()
{
if (method_info != null)
return method_info;
if (method != IntPtr.Zero) {
if (!method_is_virtual)
method_info = (MethodInfo) RuntimeMethodInfo.GetMethodFromHandleNoGenericCheck (new RuntimeMethodHandle (method));
else
method_info = GetVirtualMethod_internal ();
}
return method_info;
}
DelegateData CreateDelegateData ()
{
DelegateData delegate_data = new DelegateData ();
if (method_info.IsStatic) {
if (_target != null) {
delegate_data.curried_first_arg = true;
} else {
MethodInfo? invoke = GetType ().GetMethod ("Invoke");
if (invoke != null && invoke.GetParametersCount () + 1 == method_info.GetParametersCount ())
delegate_data.curried_first_arg = true;
}
}
return delegate_data;
}
static bool InternalEqualTypes (object source, object value)
{
return source.GetType () == value.GetType ();
}
[MethodImplAttribute (MethodImplOptions.InternalCall)]
private protected extern static MulticastDelegate AllocDelegateLike_internal (Delegate d);
[MethodImplAttribute (MethodImplOptions.InternalCall)]
static extern Delegate? CreateDelegate_internal (Type type, object? target, MethodInfo info, bool throwOnBindFailure);
[MethodImplAttribute (MethodImplOptions.InternalCall)]
extern MethodInfo GetVirtualMethod_internal ();
}
}